Tonneau cover devices are installed in vehicles to conceal cargo compartments. A tonneau cover device includes a hard or soft tonneau cover that moves in a horizontal direction of the vehicle above a cargo compartment. Japanese Laid-Open Patent Publication No. 2010-12984 describes an example of a tonneau cover device that electrically moves a tonneau cover. One example of a tonneau cover device in the related art will now be described with reference to FIG. 1. As shown in FIG. 1, the tonneau cover device includes a tonneau cover unit 40, which is arranged at the inner side of a hatchback door 45. The tonneau cover unit 40 includes a motor 41 serving as a driving unit, a tonneau cover 42, a roller 43, a case 46, two guides 48, and a link mechanism 49.
The roller 43 is rod-shaped. The roller 43 is supported by the case 46 to be rotatable about its axis, which extends in the lateral direction of the vehicle (direction orthogonal to the plane of FIG. 1). The tonneau cover 42 includes a basal end fixed to the circumferential surface of the roller 43. A spring (not shown) serving as a biasing member is attached to the roller 43 to bias it in a rotation direction in which the roller 43 rolls up the tonneau cover 42. Thus, the roller 43 rolls out the tonneau cover 42 while rotating against the biasing force of the spring.
Referring to FIG. 2, the link mechanism 49 is arranged under the tonneau cover 42. The link mechanism 49 is extended and retracted in the front to rear direction by the motor 41. The tonneau cover 42 includes a distal end fixed to the link mechanism 49. When the link mechanism 49 is extended by the motor 41 and the roller 43 rolls out the tonneau cover 42, the spring that biases the roller 43 applies tension to the tonneau cover 42. The link mechanism 49 includes distal members 49a, which project sideward from opposite sides of the distal end of the tonneau cover 42. The two guides 48 are arranged in a cargo compartment 50 of a vehicle and extend in the front to rear direction of the vehicle. The two guides 48 face each other in the lateral direction of the vehicle. When the motor 41 is driven in a state in which the hatchback door 45 is closed, the distal members 49a and the tonneau cover 42 move along the guides 48 in accordance with the extension and retraction of the link mechanism 49.
The distal end of the tonneau cover 42 moves between a storage position and an extension position. When in the storage position, the tonneau cover 42 is rolled up around the roller 43 and stored in the case 46. When in the extension position, the tonneau cover 42 is completely rolled out from the roller 43. In this state, the distal end of the tonneau cover 42 is arranged in the vicinity of the rear surface of a rear seat. When the tonneau cover 42 is located at the storage position, the cargo compartment 50 is exposed and visible from the exterior of the vehicle through a window glass 45a in the hatchback door 45. When the tonneau cover 42 is located at the extension position, the tonneau cover 42 conceals the cargo compartment 50.
In the tonneau cover device, the tonneau cover 42 moves in cooperation with the opening and closing of the hatchback door 45. The tonneau cover 42 moves from the storage position to the extension position when the hatchback door 45 closes and moves from the extension position to the storage position when the hatchback door 45 opens. The open and closed states of the hatchback door 45 may be detected by, for example, a courtesy switch. The courtesy switch is activated when the hatchback door 45 opens.